In my opinion I think giving yourself a "little age" is kind of silly. Everyone is different, and sometimes that means feeling more little one day. Then feeling maybe bigger the next day.
To kind of explain I'll use myself as an example. I totally identify as a baby boy. There are days when all I want to do is put a little appropriate movie and just lay around and snuggle my blankies and stuffy friend. I'm always diapered, when I get little time, and using them makes me feel very babyish. There are other days when I like to do more independent things like colour or draw! At the same time, I have to deal with being alone, so I do always have to do big boy stuff like feed or change myself, and get dressed. Even though I don't want to lolol